Hard track use upgrades

AMG GTThe GT/GT S is the second sports car developed entirely in-house by Mercedes-AMG. Its front mid-engine design with a rear transaxle, the use of aluminium lightweight construction and its newly developed AMG 4.0-liter V8 biturbo engine underscores the hallmark of AMG driving performance.

I'm not a track guy and will never drive my own GTS on a track since I don't want to see the same corner twice in the same day but I do drive in the canyons here in LA..
I am running Cup 2 tires and adjustable height KW coil overs.
I do have the car 4 turns from maxed out on the rear spring seat.

I did a little test with the next firmer [60-70-250* to 70-70-250*] KW spring in the rear and the car handles really nice without any squat on corner exit keeping the cornering grip on the front tires.
I will be removing the rear KW helper springs today to get the car back to the height settings I had before...

I was comparing the front brakes of an Aston Martin and the GTS and noticed that the Aston had these neat front brake cooling scoops mounted to the uprights...
They look functional as long as ya don't get into the gravel...

I'm not a track guy and will never drive my own GTS on a track since I don't want to see the same corner twice in the same day but I do drive in the canyons here in LA..
I am running Cup 2 tires and adjustable height KW coil overs.
I do have the car 4 turns from maxed out on the rear spring seat.

I did a little test with the next firmer [60-70-250* to 70-70-250*] KW spring in the rear and the car handles really nice without any squat on corner exit keeping the cornering grip on the front tires.
I will be removing the rear KW helper springs today to get the car back to the height settings I had before...

I just finished up the rear spring settings, instead of removing the helper spring completely to lower the ride, I decided to cut it in half in order to use the KW spring seat..
The car now has the ride and ride height I want..
Zero understeer, zero squat on corner exit and still sits cool...

I run with TC for my very first session in GT R and the autobrake triggered quite a few times when I was following close to a ACR.
I turned the TC off and never had that problem again. If you turn the TC off and go to the brake assist manu, it will says brakes assist not abiliable. So I suppose every assist is off when you have TC off.

One thing that MB should have done in the GTR, and could still do is this: when set to ‘R’ mode all of the active safety features such as Crash Mitigation, etc should be automatically deactivated. Then all the owner has to do is turn off ESC, and then turn the TC knob to whatever setting they and the specific track needs.

Having any Active safety features like an ‘auto brake’ function is dangerous on a road course.

I run with TC for my very first session in GT R and the autobrake triggered quite a few times when I was following close to a ACR.
I turned the TC off and never had that problem again. If you turn the TC off and go to the brake assist manu, it will says brakes assist not abiliable. So I suppose every assist is off when you have TC off.

just tried it and you’re right, it says inoperative! Hopefully this means totally off, I’ll test on track soon!

even MB test drivers haven’t mentioned this when questioned, such poor info.

I run with TC for my very first session in GT R and the autobrake triggered quite a few times when I was following close to a ACR.
I turned the TC off and never had that problem again. If you turn the TC off and go to the brake assist manu, it will says brakes assist not abiliable. So I suppose every assist is off when you have TC off.

can you verify something:

ESC is turned off by the center console switch, whereas TC is varied by adjusting the ‘yellow’ knob in the center of the dash on the GTR.

when you say you’re turning off “TC”, are you going to ‘Race’ mode; turning off ESC and then ‘Active Braking’ is disabled or are you also completely turning off TC via the center knob?

Interesting idea, I run TC off (ie use the dial) quite a bit in the dry. To be honest I can't remember if its triggered in that scenario or not.

Lots of unexplained settings on the car. It doesn't mention anywhere that RWS is only active in S+ and Race but it is. Anyone looking to drift their GTR should do it in S, much more predictable!

I don't know how may be different between the GTC and GTR - or on USA models vs other regions, but in the States with the GTC RWS is active in all driving modes (under 62mpg). You can sit at a standstill and go from lock to lock with the steering wheel and watch the rear wheels go in the opposite direction. I've demonstrated it to people in the garage! The following is from the GTC manual where it is called rear axle steering as opposed to rear wheel steering on MB's USA site:

I don't know how may be different between the GTC and GTR - or on USA models vs other regions, but in the States with the GTC RWS is active in all driving modes (under 62mpg). You can sit at a standstill and go from lock to lock with the steering wheel and watch the rear wheels go in the opposite direction. I've demonstrated it to people in the garage! The following is from the GTC manual where it is called rear axle steering as opposed to rear wheel steering on MB's USA site:

I was told this at MB World in the UK. I was doing some drifting with an instructor in their demonstrator GTR.

The car drifts much easier in S than in S+ or R, instructor said that this was because RWS is off in S in the other 2 mods its on and the RWS fights against the drift. All I can say is that the car was way easier to drift in S.

I think it will be up to us, the owners who want to track the car to find out who makes the rotors, and hence what our options are re: replacement rotors and pad options. Since so few of these cars have been tracked yet, except perhaps at the AMG Academy, there’s just no data out there.

I think that an email/call to ST, etc asking them what options are available (or will be availability) will be the way to deal with this. But at this point in time the aftermarket retailers have no incentive to spend the time, their money developing replacement parts for a very small number of potential customers. It a ‘Catch 22’ currently.

Hopefully Jeff Ritter at AP Racing might know something about sizes of the CCMs; pads, etc. I’ll reach out to him. The ultimate solution would of course be one of their replacement endurance front/rear caliper/pad setups.

Re: Racing harness/cage/bar:

Installing the cage from the ROW ‘Clubsport’ version that’s currently testing will probably be the answer for this, or one of the MB/AMG tuners might come up with a solution. I am at an age now that I just rely of the active and passive safety systems inherent in the car, so won’t be installing 5/6 points and a cage.

Re: Tyres:

The R03 option tyre, (which we can’t get from the factory here in the US), is the exact same MPSC2 ZP tyre found on the Z07 version of the C7 Corvette:

The above link not only shows the MPSC2 ZP tyres which are great track tyres and useable on the street; (just be careful in the wet and cold), but also shows two other street choices for the GTR. I would never ruin the handling by installing the Continentals, but the MPSS are a great DD tyre. Plus the new PS4 is supposed to be out soon.

Re: Brake fluid:

This is why the HPDE Gods created Castrol SRF! lol

Re: Alignment:

I mentioned above that the factory alignment is pretty aggressive and I’m anxious to see how it works on my first track weekend in 4 weeks. Alignment changes are not easy/quick as the car uses shims instead of eccentric bolts for adjustment, but the good thing is that when you have an alignment you like, it won’t change.

I actually just did the 1 day AMG Academy event at Laguna Seca on monday and was surprised to see that one of the GTS cars i drove had 9800 miles on it. The car drove and felt just like new.
Also i noticed the difference in the GTS with regular brakes and also in a GTS or a GTR with Ceramic brakes. Considerable noticeable difference on the track as the ceramics were more consistent and had a much stronger bite.

I actually just did the 1 day AMG Academy event at Laguna Seca on monday and was surprised to see that one of the GTS cars i drove had 9800 miles on it. The car drove and felt just like new.
Also i noticed the difference in the GTS with regular brakes and also in a GTS or a GTR with Ceramic brakes. Considerable noticeable difference on the track as the ceramics were more consistent and had a much stronger bite.

I didn't feel any difference between the brakes on track, what I did feel was a huge difference between the two in the spring rates in braking and corner exit.
The GTR with it's higher spring rates felt just right to me, unfortunately not one person from Mercedes could tell me what the spring rates were..just stiffer

I didn't feel any difference between the brakes on track, what I did feel was a huge difference between the two in the spring rates in braking and corner exit.
The GTR with it's higher spring rates felt just right to me, unfortunately not one person from Mercedes could tell me what the spring rates were..just stiffer

"MICHELIN Pilot Sport CUP 2 is a track tire (semi slick tire), which meets the legal requirements for use on the public highway. This tire has been specifically optimized for use on a dry track. On a wet track or road, where there is a risk of aquaplaning, adapt your driving style by reducing your speed and leaving the safety and driver assistance systems connected

For track and road handling reasons, the fitting of a set of 4 MICHELIN Pilot Sport Cup 2 is strongly advised

Before Fast Circuit Use always
o Verify the condition of your tyres, checking for wear & damage
o Build up to the temperature of the tyres gradually by a few more moderate paced laps

After running on the circuit and before returning to the road, consider
• Always check the condition of your tyres to ensure they are safe and comply with relevant local traffic laws
• Allow the tyres to cool ideally before making appropriate pressure adjustments
• Re-adjust your cold tyre pressures in accordance with the pressure recommended by the car manufacture
• If they have been disconnected/switch off, re-instate all safety systems, driver aids and tyre pressure monitoring

CAUTION !
• If not used for a prolonged period of time, remove the MICHELIN Pilot Sport Cup 2 tyres (mounted on their wheels) and reduce their pressure to half their normal value to store
• Store tyres in a clean, dry area, away from direct sunlight and above 0°C (32°F) in accordance with the information provided by Michelin in technical documentation or their website
• Do Not use, store or handle MICHELIN Pilot Sport Cup 2 tyres at ambient temperatures below -10°C (14°F)
• Under these conditions the tyre components can degrade, resulting in reduced performance, and at low temperatures can lead to cracks in the tyre compound and hence reduce potential in use
• Never use a tyre with cracks, breaks or damage to the sidewall or tread. If in any doubt please consult your local Michelin technical department
• When using for long periods in an intensive manner on circuits, please be aware that damage can occur to the tyre and its carcass from regularly running over the kerbs at the side of the circuit
• In the case of prolonged running over the kerbs (or also running heavily off the track) it is advisable to verify the internal condition of the tyre and it’s construction by demounting it from the wheel and having it professionally inspected for any damage, both on the interior and the exterior of the tyre
• It is advisable to visually check the tyres after each run, prior to going back onto the circuit"

I didn't feel any difference between the brakes on track, what I did feel was a huge difference between the two in the spring rates in braking and corner exit.
The GTR with it's higher spring rates felt just right to me, unfortunately not one person from Mercedes could tell me what the spring rates were..just stiffer

Oh yeah the tire pressures were 37psi. hot all around for best grip..

It’s been reported that GTR chassis was significantly stiffened and spring rate reduced. In addition, shock rate increased in sport modes. That was what my impression was when driving GTR. Much more compliant Car over abrupt surfaces and less bounce.